Objective:To investigate the correlation between leucine-rich α2 glycoprotein (LRG) and endoscopic activity in patients with Crohn′s disease (CD), based on the assessment of inflammation in small intestinal lesion by double-balloon enteroscope (DBE).Methods:From 15 August 2022 to 22 August 2023, the clinical data of 139 patients with small bowel CD diagnosed by DBE at the First Affiliated Hospital of Anhui Medical University were prospectively collected, which included fecal calprotectin (FC), C-reactive protein (CRP), white blood cell count, hemoglobin, albumin, Crohn′s disease activity index (CDAI), and simple endoscopic score for Crohn′s disease (SES-CD). According to the SES-CD, endoscopic activity was classified as mucosal healing (0), endoscopic remission (0 to 2), mild activity (3 to 6), moderate activity (7 to 15), and severe activity (≥16). LRG levels were detected in all patients. Spearman rank correlation was used to analyze the correlation between LRG, clinical biochemical parameters and endoscopic scores. Receiver operating characteristic curve (ROC) was performed to determine the optimal cut-off value of LRG for evaluating endoscopic mucosal healing. Mann-Whitney U test, Kruskal-Wallis H test, and Bonferroni corrected test were used for statistical analysis. Results:Among 139 patients with small bowel CD, the LRG level was 17.3 (13.0, 25.2) mg/L, and SES-CD was 5 (1, 9); 32 patients achieved mucosal healing, 50 patients achieved endoscopic remission; 39 patients had mild activity, 40 patients had moderate activity, and 10 patients had severe activity. The SES-CD was negatively correlated with both hemoglobin and albumin ( r=-0.177 (95% confidence interval, 95% CI: -0.334 to -0.011), -0.293 (95% CI: -0.438 to -0.133)), with statistical significance ( P=0.037, <0.001). The SES-CD was positively correlated with CRP, CDAI, LRG and FC ( r=0.344 (95% CI: 0.188 to 0.482), 0.429 (95% CI: 0.282 to 0.556), 0.525 (95% CI: 0.393 to 0.636), 0.661 (95% CI: 0.556 to 0.745)), with statistical significant (all P<0.001). For the 64 small bowel CD patients with CRP in the normal reference value, SES-CD was positively correlated with CDAI, LRG and FC ( r=0.296 (95% CI: 0.054 to 0.505), 0.364 (95% CI: 0.129 to 0.559), 0.547 (95% CI: 0.348 to 0.699)), with statistical significance ( P=0.017, =0.003, <0.001). The LRG level of patients with endoscopic mucosal healing was significantly lower than that of patients with endoscopic remission (11.5 (10.1, 17.2) mg/L vs. 17.3 (13.4, 23.5) mg/L), with statistical significance ( Z=-3.25, P<0.001). ROC analysis showed that the area under the curve (AUC) of LRG in predicting endoscopic mucosal healing was 0.81 (95% CI: 0.73 to 0.89), with an optimal cut-off value of 15.27 mg/L. The sensitivity, specificity, positive predictive value and negative predictive value were 0.757, 0.718, 0.900 and 0.469, respectively. The accuracy of the combination of LRG and FC (AUC was 0.88, 95% CI: 0.82 to 0.94) in predicting endoscopic mucosal healing was higher than that of LRG alone (AUC was 0.81, 95% CI: 0.73 to 0.89), and the difference was statistically significant ( P=0.011). Conclusion:Based on the results of DBE, LRG may be a reliable biomarker for predicting endoscopic remission and mucosal healing in patients with small bowel CD.

Objective:To investigate the correlation between leucine-rich α2 glycoprotein (LRG) and endoscopic activity in patients with Crohn′s disease (CD), based on the assessment of inflammation in small intestinal lesion by double-balloon enteroscope (DBE).Methods:From 15 August 2022 to 22 August 2023, the clinical data of 139 patients with small bowel CD diagnosed by DBE at the First Affiliated Hospital of Anhui Medical University were prospectively collected, which included fecal calprotectin (FC), C-reactive protein (CRP), white blood cell count, hemoglobin, albumin, Crohn′s disease activity index (CDAI), and simple endoscopic score for Crohn′s disease (SES-CD). According to the SES-CD, endoscopic activity was classified as mucosal healing (0), endoscopic remission (0 to 2), mild activity (3 to 6), moderate activity (7 to 15), and severe activity (≥16). LRG levels were detected in all patients. Spearman rank correlation was used to analyze the correlation between LRG, clinical biochemical parameters and endoscopic scores. Receiver operating characteristic curve (ROC) was performed to determine the optimal cut-off value of LRG for evaluating endoscopic mucosal healing. Mann-Whitney U test, Kruskal-Wallis H test, and Bonferroni corrected test were used for statistical analysis. Results:Among 139 patients with small bowel CD, the LRG level was 17.3 (13.0, 25.2) mg/L, and SES-CD was 5 (1, 9); 32 patients achieved mucosal healing, 50 patients achieved endoscopic remission; 39 patients had mild activity, 40 patients had moderate activity, and 10 patients had severe activity. The SES-CD was negatively correlated with both hemoglobin and albumin ( r=-0.177 (95% confidence interval, 95% CI: -0.334 to -0.011), -0.293 (95% CI: -0.438 to -0.133)), with statistical significance ( P=0.037, <0.001). The SES-CD was positively correlated with CRP, CDAI, LRG and FC ( r=0.344 (95% CI: 0.188 to 0.482), 0.429 (95% CI: 0.282 to 0.556), 0.525 (95% CI: 0.393 to 0.636), 0.661 (95% CI: 0.556 to 0.745)), with statistical significant (all P<0.001). For the 64 small bowel CD patients with CRP in the normal reference value, SES-CD was positively correlated with CDAI, LRG and FC ( r=0.296 (95% CI: 0.054 to 0.505), 0.364 (95% CI: 0.129 to 0.559), 0.547 (95% CI: 0.348 to 0.699)), with statistical significance ( P=0.017, =0.003, <0.001). The LRG level of patients with endoscopic mucosal healing was significantly lower than that of patients with endoscopic remission (11.5 (10.1, 17.2) mg/L vs. 17.3 (13.4, 23.5) mg/L), with statistical significance ( Z=-3.25, P<0.001). ROC analysis showed that the area under the curve (AUC) of LRG in predicting endoscopic mucosal healing was 0.81 (95% CI: 0.73 to 0.89), with an optimal cut-off value of 15.27 mg/L. The sensitivity, specificity, positive predictive value and negative predictive value were 0.757, 0.718, 0.900 and 0.469, respectively. The accuracy of the combination of LRG and FC (AUC was 0.88, 95% CI: 0.82 to 0.94) in predicting endoscopic mucosal healing was higher than that of LRG alone (AUC was 0.81, 95% CI: 0.73 to 0.89), and the difference was statistically significant ( P=0.011). Conclusion:Based on the results of DBE, LRG may be a reliable biomarker for predicting endoscopic remission and mucosal healing in patients with small bowel CD.

Objective:To explore the expression level and clinical significance of low-density granulocytes (LDGs) in peripheral blood of patients with inflammatory bowel disease (IBD) .Methods:A cross-sectional survey was conducted. Clinical data of IBD patients admitted to the Department of Gastroenterology, the First Affiliated Hospital of Anhui Medical University from August 2022 to January 2023 were collected. A total of 45 healthy people were enrolled as the normal control group. Simple endoscopic score for Crohn′s disease (SES-CD) was used to evaluate the activity of Crohn′s disease (CD) and Mayo endoscopic score (MES) was used to evaluate the activity of ulcerative colitis (UC). Laboratory indicators included LDGs, white blood cell count (WBC), hemoglobin (HB), platelet count (PLT), C-reactive protein (CRP), neutrophil to lymphocyte ratio (NLR), and fecal calprotectin (FC). The difference in LDGs level between IBD patients and the normal control group was statistically analyzed and the relationship between LDGs level and clinical characteristics of IBD patients was analyzed. Receiver operating characteristic (ROC) curve was used to calculate the predictive value of LDGs for the disease activity of IBD.Results:A total of 130 IBD patients were included, including 83 CD patients and 47 UC. Compared with the normal control group, the LDGs levels of patients in the CD group and UC group were respectively higher[CD: 0.53% (0.32%, 1.41%) vs. 0.19% (0.12%, 0.29%), H= 57.71, P<0.001; UC: 0.87% (0.43%, 1.90%) vs. 0.19% (0.12%, 0.29%), H= 73.23, P<0.001]. Compared with the CD patients in remission phase, the level of LDGs in active CD patients was higher ( P<0.001). Compared with the CD patients in mild activity phase, the LDGs levels of CD patients in moderate and severe activity phases were higher (all P<0.05). In terms of different disease behaviours, the level of LDGs in stricturing CD patients was the highest [1.37% (0.91%, 3.06%), all P<0.05]. Compared with the UC patients in remission phase, the level of LDGs in active UC patients was higher ( P<0.001). Compared with the UC patients in mild activity phase, the LDGs levels of UC patients in moderate and severe activity phases were higher (all P<0.05). In the CD group, LDGs level was positively correlated with CRP, FC, NLR, PLT, simple Crohn′s disease activity index (CDAI), and SES-CD ( r= 0.374, 0.548, 0.345, 0.284, 0.764, 0.721, all P<0.05). In the UC group, LDG levels was positively correlated with CRP, FC, NLR, Sutherland disease activity index (DAI), and MES ( r= 0.325, 0.666, 0.474, 0.638, 0.740, all P<0.05). In CD patients, the cut-off value of LDGs was 0.565%, with the area under curve (AUC) of 0.873, sensitivity of 73.50%, and specificity of 99.30%. In UC patients, the cut-off value of LDGs was 0.545%, with the AUC of 0.877, sensitivity of 76.90%, and specificity of 100.00%. Conclusion:The expression of LDGs in IBD patients is significantly high, which correlates with the disease activity and may be used as a biological marker for the clinical evaluation of IBD patients.

Objective:To explore the expression level and clinical significance of low-density granulocytes (LDGs) in peripheral blood of patients with inflammatory bowel disease (IBD) .Methods:A cross-sectional survey was conducted. Clinical data of IBD patients admitted to the Department of Gastroenterology, the First Affiliated Hospital of Anhui Medical University from August 2022 to January 2023 were collected. A total of 45 healthy people were enrolled as the normal control group. Simple endoscopic score for Crohn′s disease (SES-CD) was used to evaluate the activity of Crohn′s disease (CD) and Mayo endoscopic score (MES) was used to evaluate the activity of ulcerative colitis (UC). Laboratory indicators included LDGs, white blood cell count (WBC), hemoglobin (HB), platelet count (PLT), C-reactive protein (CRP), neutrophil to lymphocyte ratio (NLR), and fecal calprotectin (FC). The difference in LDGs level between IBD patients and the normal control group was statistically analyzed and the relationship between LDGs level and clinical characteristics of IBD patients was analyzed. Receiver operating characteristic (ROC) curve was used to calculate the predictive value of LDGs for the disease activity of IBD.Results:A total of 130 IBD patients were included, including 83 CD patients and 47 UC. Compared with the normal control group, the LDGs levels of patients in the CD group and UC group were respectively higher[CD: 0.53% (0.32%, 1.41%) vs. 0.19% (0.12%, 0.29%), H= 57.71, P<0.001; UC: 0.87% (0.43%, 1.90%) vs. 0.19% (0.12%, 0.29%), H= 73.23, P<0.001]. Compared with the CD patients in remission phase, the level of LDGs in active CD patients was higher ( P<0.001). Compared with the CD patients in mild activity phase, the LDGs levels of CD patients in moderate and severe activity phases were higher (all P<0.05). In terms of different disease behaviours, the level of LDGs in stricturing CD patients was the highest [1.37% (0.91%, 3.06%), all P<0.05]. Compared with the UC patients in remission phase, the level of LDGs in active UC patients was higher ( P<0.001). Compared with the UC patients in mild activity phase, the LDGs levels of UC patients in moderate and severe activity phases were higher (all P<0.05). In the CD group, LDGs level was positively correlated with CRP, FC, NLR, PLT, simple Crohn′s disease activity index (CDAI), and SES-CD ( r= 0.374, 0.548, 0.345, 0.284, 0.764, 0.721, all P<0.05). In the UC group, LDG levels was positively correlated with CRP, FC, NLR, Sutherland disease activity index (DAI), and MES ( r= 0.325, 0.666, 0.474, 0.638, 0.740, all P<0.05). In CD patients, the cut-off value of LDGs was 0.565%, with the area under curve (AUC) of 0.873, sensitivity of 73.50%, and specificity of 99.30%. In UC patients, the cut-off value of LDGs was 0.545%, with the AUC of 0.877, sensitivity of 76.90%, and specificity of 100.00%. Conclusion:The expression of LDGs in IBD patients is significantly high, which correlates with the disease activity and may be used as a biological marker for the clinical evaluation of IBD patients.

Objective : To investigate the effect of platelet particles on the extent of intestinal inflammation and in⁃ testinal mucosal permeability in mice with dextran sodium sulfate induced colitis. Methods : The experiment was divided into four groups : normal control group ( n = 10 , drinking sterile distilled water + intraperitoneal injection of 0. 9% sodium chloride solution) , PMPs group ( n = 10 , drinking sterile distilled water + intraperitoneal injection of PMPs) , DSS model group ( n = 10 , drinking DSS solution + intraperitoneal injection of 0. 9% sodium chloride solution) , and experimental group ( n = 15 , drinking DSS solution + intraperitoneal injection of PMPs) . Peripheral blood⁃derived PMPs suspension was collected from inflammatory bowel disease ( IBD) patients. A colitis model was constructed in mice by allowing them to freely drink a 5% DSS solution for 1 week , followed by continuous intraperitoneal injection of PMPs for 7 days. Disease activity index (DAI) scores was recorded daily and the severity of intestinal inflammation with histopathological scores (HI) was assessed by HE staining of colon samples at the end of the experiment. Myeloperoxidase (MPO) , neutrophil elastase (NE) , citrullinated histone H3 (citH3) , and free DNA levels were measured in colon homogenate , observe intestinal mucosal structure by transmission electron microscopy , and intestinal permeability was tested using fluorescein isothiocyanate⁃dextran (FITC⁃D) . Results: Compared with the normal control group , the colonic mucosa of mice in the PMPs group showed edema , severe destruction of epithelial structure , extensive aggregation of inflammatory cells , and increased overall HI score (P < 0. 01) ; the levels of inflammatory factors such as IL⁃1β and TNF⁃α in colonic tissue homogenates of mice in the PMPs group increased (P < 0. 05) , and the expression of NETs increased (P < 0. 05) ; the plasma FITC⁃D level of mice in the PMPs group significantly increased (P < 0. 05) , and the permeability of intestinal mucosa increased. Compared with the DSS group , the experimental group mice had higher plasma FITC⁃D levels ( P < 0. 05 ) and more electron microscopic colonic epithelial damage. Conclusion PMPs induces NETs formation in mice , promotes colonic inflammation in mice , increases intestinal mucosal permeability and aggravates intestinal inflammation in mice with DSS colitis.

Objective:To investigate the clinical effect of early bronchoalveolar lavage on patients with aspiration pneumonia.Methods:A retrospective study was conducted on 55 patients with aspiration pneumonia who met inclusion criteria but not exclusion criteria in the Intensive Care Department of our hospital from January 2020 to April 2021. The patients were divided into the control group (32 cases) and the bronchoscopic lavage group (23 cases) according to whether they received bronchoscopic lavage within 24 h after aspiration. Basic information (sex, age, body mass index, chest X-ray score, oxidation index, temperature, heart rate, respiratory rate, white blood cells, PCT, IL-6, CPR and APACHE Ⅱ score), etiology changes at the early stage (≤ 3 d) and later stage (4-7 d after admission), and changes in prognostic indexes (mechanical ventilation time, length of ICU stay, length of stay and mortality) were compared between the two groups. The clinical efficacy of early endoscopy lavage for aspiration pneumonia was evaluated.Results:The positive rate of early etiological culture was 85.2%, the bacterial positive rate was 72.9% and the fungal positive rate was 14.6%. Pseudomonas aeruginosa accounted for 20.8%, Klebsiella pneumoniae accounted for 14.6%, Staphylococcus aureus and Streptococcus accounted for 12.5%, and there was no significant difference in the distribution between the bronchoscopic lavage group and the control group (all P>0.05). The positive rate of late etiological culture was 88.6%, the bacterial positive rate was 85.7% and the fungal positive rate was 2.9%. The positive rate of late bacterial culture was significantly decreased in the bronchoscopic lavage group ( P < 0.05), and the other results were not significantly different from the control group (all P>0.05). After early bronchoscopic lavage, the duration of mechanical ventilation, length of ICU stay and length of stay were significantly shortened, and the fifth day CPIS score was significantly decreased (all P< 0.05). Conclusions:Early endotracheal lavage can reduce mechanical ventilation time, length of ICU stay and length of stay of aspiration pneumonia, and reduce the positive rate of bacterial culture in the lung at the later stage, which needs to be further verified by a large randomized controlled study.

Background::The calcineurin inhibitor (CNI)-based immune maintenance regimen that is commonly used after renal transplantation has greatly improved early graft survival after transplantation; however, the long-term prognosis of grafts has not been significantly improved. The nephrotoxicity of CNI drugs is one of the main risk factors for the poor long-term prognosis of grafts. Sirolimus (SRL) has been employed as an immunosuppressant in clinical practice for over 20 years and has been found to have no nephrotoxic effects on grafts. Presently, the regimen and timing of SRL application after renal transplantation vary, and clinical data are scarce. Multicenter prospective randomized controlled studies are particularly rare. This study aims to investigate the effects of early conversion to a low-dose CNI combined with SRL on the long-term prognosis of renal transplantation.Methods::Patients who receive four weeks of a standard regimen with CNI + mycophenolic acid (MPA) + glucocorticoid after renal transplantation in multiple transplant centers across China will be included in this study. At week 5, after the operation, patients in the experimental group will receive an additional administration of SRL, a reduction in the CNI drug doses, withdrawal of MPA medication, and maintenance of glucocorticoids. In addition, patients in the control group will receive the maintained standard of care. The patients’ vital signs, routine blood tests, routine urine tests, blood biochemistry, serum creatinine, BK virus (BKV)/cytomegalovirus (CMV), and trough concentrations of CNI drugs and SRL at the baseline and weeks 12, 24, 36, 48, 72, and 104 after conversion will be recorded. Patient survival, graft survival, and estimated glomerular filtration rate will be calculated, and concomitant medications and adverse events will also be recorded.Conclusion::The study data will be utilized to evaluate the efficacy and safety of early conversion to low-dose CNIs combined with SRL in renal transplant patients.Trial registration::Chinese Clinical Trial Registry, ChiCTR1800017277.

Objective To investigate the changes and formation mechanism of plasma endothelial microparticles (EMPs) in patients with acute pancreatitis (AP). Methods Blood samples were collected from 60 patients with AP who were treated in The First Affiliated Hospital of Anhui Medical University from August 2020 to June 2021, and these patients were divided into mild acute pancreatitis (MAP) group with 23 patients, moderate-severe acute pancreatitis (MSAP) group with 23 patients, and severe acute pancreatitis (SAP) group with 14 patients; 20 individuals who underwent physical examination were enrolled as control group.Differential centrifugation was used to obtain platelet-poor plasma, flow cytometry was used to measure the level of CD31 + CD41 - EMPs, and ELISA was used to measure the levels of endothelin-1(ET-1), von Willebrand factor (vWF), nitric oxide (NO), and vascular cell adhesion molecule-1(VCAM-1).HUVECs were stimulated by the plasma of AP patients, and then flow cytometry and qRT-PCR were used to measure the changes in EMPs, reactive oxygen species (ROS), and mitochondrial membrane potential and the expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1(ICAM-1), VCAM-1, NADPH oxidase, and P-selectin.A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups.The Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between groups and within each group.The chi-square test was used for comparison of categorical data between groups, and the Pearson correlation test was used for correlation analysis. Results Compared with the control group, the MAP, MSAP, and SAP groups had a significant increase in the level of EMPs (all P < 0.05).Compared with the MAP and MSAP groups, the SAP group had a significant increase in the level of EMPs (both P < 0.05).In the patients with AP, the level of EMPs was negatively correlated with Acute Physiology and Chronic Health Evaluation Ⅱ score, Bedside Index for Severity in Acute Pancreatitis, Ranson score, CT score, and C-reactive protein ( r =0.686 2, 0.777 3, 0.713 8, 0.771 8, and 0.473 9, all P < 0.01).Compared with the control group, the MAP, MSAP, and SAP groups had significant increases in the levels of ET-1, vWF, and VCAM-1 and a significant reduction in the level of NO (all P < 0.05).Compared with the control group, the MSAP and SAP groups had the plasma that promoted the release of a large amount of EMPs (both P < 0.05).Compared with the control group, all the other groups, except the MAP group in terms of VCAM-1 and eNOS, had significant increases in the mRNA expression levels of eNOS, iNOS, ICAM-1, P-selectin, VCAM-1, and NADPH oxidase (all P < 0.05).Compared with the HC group, the MAP, MSAP, and SAP groups and the LPS group had a significant increase in the level of ROS and a significant reduction in mitochondrial membrane potential in HUVECs (all P < 0.05). Conclusion There is a significant increase in the plasma level of EMPs in AP patients, which is correlated with the severity of pancreatitis.Meanwhile, the plasma of AP patients can promote the formation of EMPs in HUVECs in vitro, which may be associated with cell oxidative injury.

Objective:To investigate the effect of cesarean scar defect and endometrial cavity fluid on the pregnancy outcomes of infertility patients with previous cesarean scar uterus undergoing in vitro fertilization-embryo transfer (IVF-ET). Methods:This was a retrospective cohort study. Totally 732 cases of patients with previous cesarean scar uterus were selected from frozen-thawed embryo transfer (FET) cycles in the Fertility Center, Shenzhen Zhongshan Urology Hospital from January 2019 to March 2020. They were divided into four groups: group A ( n=39) including patients with previous cesarean scar defect and without endometrial cavity fluid; group B ( n=82) including patients with previous cesarean scar defect and with endometrial cavity fluid; group C ( n=495) including patients without previous cesarean scar defect and without endometrial cavity fluid; group D ( n=116) including patients without previous cesarean scar defect and with endometrial cavity fluid. The general data and pregnancy outcomes were compared among these groups. Multivariate logistics regression analysis of pregnancy outcome indexes was performed. Results:The transplantation age of group A was higher than that of group B [(38.33±3.55) years vs. (36.93±3.59) years, P=0.045], the endometrial thickness of luteal transformation day and the rate of good-quality embryo transplantation of group C were higher than those of group D [(9.40±1.56) mm vs. (9.03±1.59) mm, P=0.025; 75.76% (375/495) vs. 65.52% (76/116), P=0.024]. The egg retrieval age of group A was higher than that of group C [(37.72±3.55) years vs. (36.25±4.52) years, P=0.049], but the endometrial thickness of luteal transformation day was thinner [(8.74±1.58) mm vs. (9.40±1.56) mm, P=0.012], and the differences were statistically significant. The implantation rate, the biochemical pregnancy rate and the clinical pregnancy rate of group C were higher than those of group D [34.23% (230/672) vs. 22.58% (35/155), P=0.007; 48.28% (239/495) vs. 37.93% (44/116), P=0.044; 42.83% (212/495) vs. 30.17% (35/116), P=0.012]. The early abortion rate in group D was higher than that in group B [40.00% (14/35) vs. 17.24 % (5/29), P=0.047], the difference was statistically significant. Multivariate logistics regression analyses were used with adjustment for possible confounders: the maternal age at embryo transfer, the maternal age at egg retrieval, anti-Müllerian hormone (AMH),antral follicle count (AFC), basic follicle-stimulating hormone (FSH), endometrial CD138 results, FET protocol, and embryo attributes, the number of embryos transferred, embryo quality, the endometrial thickness and the progesterone value on the day of luteal transformation, the result showed that the implantation rate, the biochemical pregnancy rate and the clinical pregnancy rate of group D were lower than those of group C [22.58% (35/155) vs. 34.23% (230/672), P=0.006; 37.93% (44/116) vs. 48.28% (239/495), P=0.047; 30.17% (35/116) vs. 42.83% (212/495), P=0.022] and the differences were statistically significant. The implantation rate, the biochemical pregnancy rate and the clinical pregnancy rate of group B were higher than those of group D [29.52% (31/105) vs. 22.58% (35/155), P=0.049; 48.78% (40/82) vs. 37.93% (44/116), P=0.012; 35.37% (29/82) vs. 30.17% (35/116), P=0.030] and the differences were statistically significant. Conclusion:Endometrial cavity fluid is the main factor that obviously affects the pregnancy outcome of infertility patients with previous cesarean scar uterus undergoing FET cycles.

Objective:To investigate the effect of cesarean scar defect and endometrial cavity fluid on the pregnancy outcomes of infertility patients with previous cesarean scar uterus undergoing in vitro fertilization-embryo transfer (IVF-ET). Methods:This was a retrospective cohort study. Totally 732 cases of patients with previous cesarean scar uterus were selected from frozen-thawed embryo transfer (FET) cycles in the Fertility Center, Shenzhen Zhongshan Urology Hospital from January 2019 to March 2020. They were divided into four groups: group A ( n=39) including patients with previous cesarean scar defect and without endometrial cavity fluid; group B ( n=82) including patients with previous cesarean scar defect and with endometrial cavity fluid; group C ( n=495) including patients without previous cesarean scar defect and without endometrial cavity fluid; group D ( n=116) including patients without previous cesarean scar defect and with endometrial cavity fluid. The general data and pregnancy outcomes were compared among these groups. Multivariate logistics regression analysis of pregnancy outcome indexes was performed. Results:The transplantation age of group A was higher than that of group B [(38.33±3.55) years vs. (36.93±3.59) years, P=0.045], the endometrial thickness of luteal transformation day and the rate of good-quality embryo transplantation of group C were higher than those of group D [(9.40±1.56) mm vs. (9.03±1.59) mm, P=0.025; 75.76% (375/495) vs. 65.52% (76/116), P=0.024]. The egg retrieval age of group A was higher than that of group C [(37.72±3.55) years vs. (36.25±4.52) years, P=0.049], but the endometrial thickness of luteal transformation day was thinner [(8.74±1.58) mm vs. (9.40±1.56) mm, P=0.012], and the differences were statistically significant. The implantation rate, the biochemical pregnancy rate and the clinical pregnancy rate of group C were higher than those of group D [34.23% (230/672) vs. 22.58% (35/155), P=0.007; 48.28% (239/495) vs. 37.93% (44/116), P=0.044; 42.83% (212/495) vs. 30.17% (35/116), P=0.012]. The early abortion rate in group D was higher than that in group B [40.00% (14/35) vs. 17.24 % (5/29), P=0.047], the difference was statistically significant. Multivariate logistics regression analyses were used with adjustment for possible confounders: the maternal age at embryo transfer, the maternal age at egg retrieval, anti-Müllerian hormone (AMH),antral follicle count (AFC), basic follicle-stimulating hormone (FSH), endometrial CD138 results, FET protocol, and embryo attributes, the number of embryos transferred, embryo quality, the endometrial thickness and the progesterone value on the day of luteal transformation, the result showed that the implantation rate, the biochemical pregnancy rate and the clinical pregnancy rate of group D were lower than those of group C [22.58% (35/155) vs. 34.23% (230/672), P=0.006; 37.93% (44/116) vs. 48.28% (239/495), P=0.047; 30.17% (35/116) vs. 42.83% (212/495), P=0.022] and the differences were statistically significant. The implantation rate, the biochemical pregnancy rate and the clinical pregnancy rate of group B were higher than those of group D [29.52% (31/105) vs. 22.58% (35/155), P=0.049; 48.78% (40/82) vs. 37.93% (44/116), P=0.012; 35.37% (29/82) vs. 30.17% (35/116), P=0.030] and the differences were statistically significant. Conclusion:Endometrial cavity fluid is the main factor that obviously affects the pregnancy outcome of infertility patients with previous cesarean scar uterus undergoing FET cycles.